1. Field of the Invention
The present invention relates to a burner having variable output structure, and more particularly, to a burner having variable output structure that can adjust an output of a burner by adjusting a position of a flame-hole plate.
2. Discussion of Background Information
In general, according to a method of burning gas fuel in a gas boiler having a premixed burner, gas and air are mixed in advance with each other at a mixture ratio corresponding to optimum combustion, and then supplied to a flame-hole surface to burn.
FIG. 1 is a schematic view showing a structure of a general burner in the related art.
The general burner includes a gas valve 10 that adjusts a pressure of gas supplied to the general burner, a nozzle 20 that injects the gas supplied through the gas valve 10, a mixture inlet 30 through which the gas injected from the nozzle 20 is mixed and supplied, an inner space 41 of the general burner 40 to which a mixture supplied through the mixture inlet 30 is supplied, and a flame-hole plate 42 that includes a plurality of flame holes 42a in order to inject the mixture supplied to the inner space 41 to a combustion chamber (not shown).
When a load required in a combustion device is large, the gas valve 10 is controlled so that the gas is supplied to the general burner at a high pressure for the purpose of a high output of the general burner. In contrast, when the load required in the combustion device is small, the gas valve is controlled so that the gas is supplied to the general burner at a low pressure for the purpose of a low output of the general burner.
In this case, a speed of the mixture, which is injected into the combustion chamber through the flame holes 42a, depends on the gas pressure that is determined by the control of the gas valve 10. That is, if the gas pressure is high, the speed of the mixture injected through the flame holes 42a will be high.
However, according to the general burner having the above-mentioned structure, when the load required in the combustion device is small, if the gas is supplied at low pressure, flames are generated on an inner surface of the flame-hole plate 42 facing an inside of the combustion chamber. As a result, there is a problem in that combustion is abnormally performed.
That is, if the speed of the mixture injected through the flame holes 42a is a predetermined speed or less, a backfire, where flames are generated in the flame holes 42a, occurs.
The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a burner having variable output structure that maintains the speed of the mixture injected through the flame holes at a predetermined speed or more by supplying gas through a gas valve at a predetermined pressure or more, and prevents an occurrence of backfire at a lowoutput by adjusting an opened area of the flame holes.